摘要 |
<p>The cutting tool is spherical and is used to machine pre-bored holes to size. It fits on a mandrel (3, 9) orientated at an acute angle to the hole axis, the shank (4) of the mandrel being parallel to the axis. The tool is a running fit (12) and can rotate. The sphere may be in one piece, or it can be built up from a number of discs. The cutting teeth (2, 8, 15) may be straight, formed on the line of plane spherical sections. The teeth may also be helical around the circumference of the sphere Positive or negative rake (7) can be used.</p> |